client/app/assets/less/inc/404.less (60 lines of code) (raw):

.four-zero { background: @white; box-shadow: 0 1px 11px rgba(0, 0, 0, 0.27); border-radius: 2px; position: absolute; top: 50%; margin-top: -150px; text-align: center; padding: 15px; height: 300px; width: 500px; left: 50%; color: #333; margin-left: -250px; h2 { font-size: 130px; } @media (max-width: @screen-xs-max) { width: ~"calc(100% - 40px)"; left: 20px; margin-left: 0; height: 260px; margin-top: -130px; h2 { font-size: 90px; } } h2 { line-height: 100%; font-weight: 100; } small { display: block; font-size: 26px; margin-top: -10px } footer { background: @ace; position: absolute; left: 0; bottom: 0; width: 100%; padding: 10px; & > a { font-size: 21px; display: inline-block; color: #333; margin: 0 1px; line-height: 40px; width: 40px; height: 40px; background: rgba(0, 0, 0, 0.09); border-radius: 50%; text-align: center; &:hover { background: rgba(0, 0, 0, 0.2); } } } }